The present invention relates generally to labeling devices and, more particularly, to labeling devices of the type used to apply labels to an array of packages in form, fill and seal packaging machines or other types of package thermoforming devices. The invention also relates to a method of applying labels using such labeling devices.
Horizontal form-fill-seal machines are conventionally used in the packaging industry to package a wide variety of products in a generally automated assembly-line process. In such machines, continuous rolls of plastic film are used to form the top and bottom of the product packaging in a step-wise, indexing fashion. The products are typically placed on the bottom film after it has been suitably formed to create individual receptacles for the products. The top film is then applied to the bottom film and heat sealed together around the perimeter of the products. The individual product packages may then be separated from each other in a cutting operation.
Labeling of the product packages with product information and other indica in the horizontal form-fill-seal machines described above can be accomplished using conventional labeling devices that apply the labels to the top film before the top film is joined to the bottom film. These conventional labeling devices are normally mounted to the top of the horizontal form-fill-seal machines in a semi-permanent manner, making them difficult to quickly uninstall for use on another form-fill-seal machine. The conventional labeling devices also require rerouting of the top film rerouted through the labeling device, which complicates initial setup of the horizontal form-fill-seal machines. The rerouting of the top film can increase the risk that the top film will not track appropriately, leading to additional machine down-time and product and/or label waste.
The positioning of the conventional labeling devices at the top of horizontal form-fill-seal machines is undesirable because the horizontal form-fill-seal machines may index up to ten times before the labels are advanced with the top film to the machine location where the product package is formed. This can cause significant wasting of product and/or labels during each startup of the horizontal form-fill-seal machines, particularly if the labels or the top film must be repeatedly readjusted to achieve the desired alignment during startup or operation of the machines. Because of the remote location of conventional labeling devices at the top of the horizontal form-fill-seal machines, it may also be difficult to access the labeling devices during initial threading of the top film through the labeling devices as well as during reloading of the labels. A need has thus developed for an improved labeling device.